Lab talk

May 9, 2012

Nanomanipulation set-up assembles single-nanoparticle electronics

Nanoparticles possess several advantages over 1D and 2D structures. For instance, in nanoparticles the carrier travelling distance is short and the carrier lifetime is long. However, connecting electrodes to a single nanoparticle is not a trivial task, which presents an obstacle to progress in areas such as electronics and optoelectronics. Devices containing randomly spread particles atop closely spaced leads made by break junction or tilt-angle evaporation techniques have been demonstrated, but developers would prefer a more routine approach.

Recently, researchers from the Institute of Physics, Academia Sinica, in Taiwan, have proposed and demonstrated a reliable approach for producing nanoparticle devices. The circuits fabricated by the team contain a single ZnO particle embedded in a nanopore structure and exhibit photovoltaic functionality with a fill factor of 48%.

Suits most materials

What’s more, the method provides a route for making electronic devices containing a single nanoparticle of virtually any material. Based on the device fabrication process, the team is now developing a technique that allows the chemical potential of an embedded nanoparticle to be tuned by a surrounding gate electrode. In this way, field-effect transistors containing a single semiconductor nanoparticle could be reproducibly constructed.

In a related project, the scientists have also used the manipulation probes to pick up selected objects such as nanowires, nanotubes and graphene sheets and place them on top of pre-prepared electrodes crossing the holes on a chip. This would allow for correlated structural TEM inspection and rigorous electrical characterization on the same specimen.

About the author

This work was conducted by a team from the Quantum Electronics Laboratory, Institute of Physics, Academia Sinica. Linh-Nam Nguyen is a PhD student enrolled in the Nano Science and Technology-Taiwan International Graduate Program. His research interests include applications of nanoparticle devices. Dr Yann-Wan Lan is the key person who developed the manipulation technique as well as the fabrication process for suspended electrodes. Prof. ChiiDong Chen is a research fellow at the Institute of Physics and is team leader. He is interested in the transport properties of nanoparticle and nanowire devices. In addition, through collaborations, he also works on molecular electronics and chemical sensors.